Clothes washer tub having step means for sediment removal

ABSTRACT

A DOMESTIC CLOTHES WASHER HAS A PAIR OF NESTED TUBS ONE OF WHICH IS IMPERFORATE TO RETAIN THE WASHING FLUID, THE ONE OF WHICH IS PERFORATE AND ROTATABLE TO CENTRIFUGE THE WASHING FLUID FROM CLOTHES BEING WASHED THEREIN. AN AGITATOR IN THE PERFORATE TUB PROVIDES A PULSATING TOROIDAL CIRCULATION OF WASHING FLUID. THE BOTTOM WALL OF THE PERFORATE TUB HAS A SERIES OF SEDIMENT REMOVAL HOLES PROTECTED FROM THE PULSING CIRCULATION OF WASHING FLUID BY AN ANNULAR STEP DOWN OUTBOARD OF THE AGITATOR. THE PROTECTION   OF THE STEP DOWN CREATES EDDY CURRENTS OVER THE HOLES DURING EACH PULSE OF WASHING FLUID TO TRAP SEDIMENT. BETWEEN EACH PULSE SEDIMENT THUS TRAPPED DROPS THROUGH THE HOLES FOR REMOVAL FROM HE CLOTHES WASHER DURING ROTATION OF SAID PERFORATE TUB.

,1 B. L. BRUCKEN 3,616,662

CLOTHES WASHER TUB HAVING STEP MEANS FOR SEDIMENT REMOVAL Filed July 17,1970 2 Shoots-Shoot 1 Z INVIiN' IOR By @2001: fix/Mm A TTORNEY Nov. 2, 1971 L. BRUCKEN 3,616,552

CLOTHES WASHER TUB HAVING STEP MEANS FOR SEDIMENT REMOVAL Filed July 17,1870 2 SheetsSheet 2 United States Patent 3,616,662 CLOTHES WASHER TUB HAVING STEP MEANS FOR SEDIMENT REMOVAL Byron L. Brucken, Dayton, Ohio, assiguor to General Motors Corporation, Detroit, Mich. Filed July 17, 1970, Ser. No. 55,883 Int. Cl. D06f 23/04, 39/10 US. CI. 68-18 D Claims ABSTRACT OF THE DISCLOSURE A domestic clothes washer has a pair of nested tubs one of which is imporforate to retain the washing fluid, the other of which is perforate and rotatable to centrifuge the washing fluid from clothes being washed therein. An agitator in the perforate tub provides a pulsating toroidal circulation of washing fluid. The bottom wall of the perforate tub has a series of sediment removal holes protected from the pulsing circulation of washing fluid by an annular step down outboard of the agitator. The protection of the step down creates eddy currents over the holes during each pulse of washing fiuid to trap sediment. Between each pulse sediment thus trapped drops through the holes for removal from the clothes washer during rotation of said perforate tub.

The removal of sediment such as sand from domestic clothes washers has long been recognized as a problem. In solid spin tub machines, it has always been difficult to centrifuge sediment through outflow ports in the top of the spin tub. Sediment removal has been more effective in perforate spin tub machines where the bottom wall of the spin tub has included substantially coextensive perforations. Such perforations, however, tend to dissipate the force of the pulsating currents of washing fluid created by the oscillations of an agitator. This invention is directed to a spin tub which has a substantially perforate sidewall to facilitate centrifuging but which includes a substantially imperforate bottom wall so that the washing energy in pulsating currents of washing fluid will not be dissipated.

Accordingly, it is a general object of this invention to provide a substantially perforate spin tub with a bottom wall having improved and simplified sediment removal means.

A more specific object of this invention is the provision in a domestic clothes washer of an annular step and hole arrangement in the bottom wall of a perforate spin tub to provide in cooperation with radially outward pulsations of washing fluid repetitive eddy currents which entrain sediment during said pulsations for disposal thereof through said hole as said eddy currents ebb between said pulsations.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

FIG. 1 is a fragmentary side elevational view of a domestic clothes washer with parts broken away to show a tub assembly incorporating the sediment removal means of this invention;

FIG. 2 is a sectional view taken along line 22 in FIG.

3,616,662 Patented Nov. 2, 1971 1 to show the bottom wall of the spin tub of this invention; and

FIG. 3 is an enlarged fragmentary sectional view taken in the direction of line 3 in FIG. 2.

In accordance with this invention and with reference to FIG. 1, a domestic clothes washer is shown generally at 10. The washer includes a box-like sheet metal casing 12 having a top wall 14.

The casing 12 is shown to enclose a nested tub assembly 24. The assembly includes an outer imperforate tub or water container 26 and a perforate inner tub or spin tub 28. Perforations 30 are coextensive with a cylindrical sidewall 32 of the spin tub. The sidewall 32 is curved inwardly at its lower end to form an open-bottom 34 and at its upper end to form a rim 33 which defines an open-top 36. Spin tub 28 is approximately sixteen inches deep, has a perforate sidewall 32 twenty-two inches in diameter and eleven inches high and a top opening 36 provided by rim 33 which is about nineteen inches in diameter. The open bottom 34 of the spin tub is 17.5 inches in diameter. The sidewall 27 of the water container is substantially fifteen inches high from its top to its jointure 29 with the bottom wall 31. Sidewall 27 diverges in the fifteen inches from a diameter of twenty-three inches at its top to a diameter of twenty-four inches at its bottom.

The tub assembly 24 is mounted on a suspension system shown generally at 40 and more fully taught in US. Patent 3,493,118 granted Feb. 3, 1970. The tub assembly includes an agitator 44 which with the spin tub 28 is connected to a power means shown generally at 50. The power means includes a drive mechanism which may be of a roller drive type taught more fully in US. Patent 3,087,321 granted Apr. 30, 1963. In general, the power means 50 may be operated in one manner to vertically reciprocate or oscillate the agitator 44 for washing clothes in the tub assembly. When the power means is operated in another manner, the spin tub 28 is rotated with respect to the water container 26 for centrifuging washing fluid from the clothes in the spin tub. The foregoing should provide a sufiicient understanding of the environment in which the present invention is used. For additional details, reference may be had to copending applications (55,813 and 55,814) commonly assigned with this application.

The problem in the foregoing washer is to get rid of normally insoluble sediment such as sand without dissipating the cleaning energy of the pulsating currents of washing fluid. Such energy dissipation is most pronounced where the spin tub is substantially perforated in the area receiving the most forceful currents of washing fluid from the agitator. Too many perforations or holes in this area reduce the cleaning effect of the agitator. In the clothes washer 10 the pulsating currents are created by a vertically reciprocable agitator or pulsator 44. The water container 26 contains nineteen to twenty gallons of washing fluid at maximum fill. With the power means 50 operating to reciprocate the agitator -44 at three hundred sixty strokes per minute, an eighteen pound clothes load will turn over inside the spin tub in the toroidal circulation about one-third to one-half times per minute or five to seven times per fifteen minute wash cycle. As you open up the bottom of the spin tub with holes to release sediment, you lose turnover and washability. Moreover, clothes tend to hang up on the holes of an extensively perforated bottom and circulation of washing fluid tends to take place between the water container and the spin tub rather than inside the spin tub. My desire is to keep the clothes turning over while suspended in the washing fluid inside the spin tub. My invention incorporates a novel sediment removal means in the bottom of the spin tub which releases sediment without dissipating the energy of the washing action and the washability of the clothes.

The sediment removal means includes a specially configured bottom wall 60 in the spin tub 26. The diameter of the bottom wall is 17.76 inches, a dimension which is smaller than the top opening 36 of the spin tub and slightly larger than the open-bottom 3-4 of the spin tub. This permits the bottom Wall 60 during assembly of the spin tub to be inserted through the top opening 36 to form a jointure 62 with the sidewall 32. The jointure is roll welded all around and the upper peripheral edge 64 of the bottom wall is planished all around to be smooth and free from burn-offs.

Turning now to FIG. 3, the bottom wall 60 is shown to have a generally dished configuration in cross-section. An annular step 66 circumscribes the bottom wall radially outward of an imperforate dished portion 68 thereof and of the pumping ring 45 of the agitator 44 (FIG. 1). The step is also outboard of a plurality of radial ribs 70 used to stiifen the bottom wall 60. The diameter of the step is 15.24 inches and the height of the step is determined by the merger of an inside radius 72 of .10 inch and an outside radius 74 of .18 inch.

A series 76 of sediment release holes is positioned radially outwardly of the step 66. The step and holes are as close as possible to the outer peripheral edge of the bottom wall, while still permitting the connection of the bottom wall 60 to the sidewall 32. The series 76 is made up of three concentric circles of holes also concentric with the pump ring 45 and the step 66. Holes 78 are on a circle having a diameter of 16.76 inches. Holes 80 are on a circle having a diameter of 16.38 inches. Holes 82 are on a circle having a diameter of 16.00 inches. In all, there are seventy-two holes evenly divided between the three circles and each hole having a diameter of .187 inch and spaced 5 apart.

In operation, dirty clothes are placed in the spin tub 28. The water container is filled with water which becomes washing fluid when mixed with detergent. When the power means is energized in one manner, the agitator 44 will reciprocate up and down. This moves the pump ring toward and away from the dished portion 68 of bottom wall 60. The movement toward the bottom wall creates a surging annular tide of washing fluid moving radially outwardly across the bottom wall 60. At the start of each movement away from the bottom wall, the surging annular tide will ebb. This to and fro action does several things. First, it forces surging currents of washing fluid through the clothes to release the dirt. Some of the dirt disssolves and remains in solution. Other dirt such as sand or other non-floating, insoluble sediment, drops to the imperforate dished portion along the bottom of the spin tub.

Secondly, the vertical reciprocation of the agitator sets up a toroidal circulation of washing fluid in the spin tub. This tends to turn over the clothes, thereby to continuously present different portions of the clothes to the surging currents produced by the pump ring. Additional sediment drops from the clothes as before to the bottom wall of the spin tub.

Thirdly, the surging annular tide of washing fluid is forced by the pump ring across the dished portion 68 and over the step 66. Eddy currents are thereby initiated in the annular area A. As the annular tide moves across the dished portion 68, the previously dropped sediment is pushed toward and over the step 66 where the sediment is entrained in the eddy currents of area A. The eddy currents are turbulent and keep the sediment in suspension. However, each time the pump ring reaches the end of a stroke and starts to move away from the bot- 'tom wall, there is a dead interval and the tide ebbs as do the eddy currents in area A. The sediment drops out of suspension and is released or removed through the series of holes 76 in the spin tub so that it can drop into the water container 26 for removal to drain. In a repetitive sense the reciprocations of the agitator 44 cooperate with the configuration of the bottom wall 60 to create pulsating eddy currents adjacent step A. At each pulse, sediment is entrained. Between each pulse, sediment is removed.

In the preferred embodiment the pump ring 45 has a diameter of 9.5 inches and may be selectively reciprocated by the power means 50 at speeds of two hundred forty and one hundred eightly strokes per minute in addition to the speed of three hundred sixty strokes per minute set forth in the example above. Sediment in each case will be trapped and released in accordance with the pulsating eddy current principle of my invention.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

I claim:

1. In a domestic clothes washer having an imperforate outer tub adapted to contain washing fluid and an opentop inner tub nested within said outer tub and in spaced relation thereto, said inner tub having a perforate cylindrical sidewall, agitator means adapted for movement within said inner tub, and power means drivably connected to said agitator means for moving said agitator means to provide pulsations of washing fluid radially outwardly in said inner tub to agitate clothes and remove sediment therefrom, the invention comprising sediment removal means including in said inner tub a bottom wall connected to said sidewall for facilitating sediment removal in cooperation with the pulsations of said washing fluid, said bottom wall including an annular step down radially outwardly of said agitator means and adjacent the connection of said bottom wall to said sidewall, said bottom wall including a series of holes radially outwardly of said step down and sufiiciently close to said step down to lie in the eddy current of said washing fluid during the pulsations thereof, whereby sediment removed from said clothes is carried by said washing fluid over said step down and entrained in said eddy current thereby to drop from said inner tub into said outer tub through the holes in said bottom wall as said eddy current ebbs between said pulsations.

2. The sediment removal means of claim 1 wherein the annular step down has a height of .24 inch and a diameter of 15.24 inches, and said series of holes in said bottom wall totals seventy-two each spaced 5 apart and having a diameter of .187 inch.

3. The sediment removal means. of claim 2 wherein said agitator means is a substantially conical pump ring substantially 9.5 inches in diameter, and said power means moves said agitator means vertically selectively at speeds of 360, 240 and strokes per minute.

4. The sediment removal means of claim 2 wherein said series of holes are staggered and evenly divided to lie in three concentric circles concentric with said annular step down, said concentric circles having diameters of 16 inches, 16.38 inches and 16.76 inches.

5. In a domestic clothes washer having an imperforate outer tub adapted to contain washing fluid and an opentop inner tub nested within said outer tub and in spaced relation thereto, said inner tub having a generally cylindrical perforate sidewall defining an open-bottom, agitator means adapted for reciprocation within said inner tub, and power means drivably connected to said agitator means for reciprocating said agitator means to provide pulsations of washing fluid radially outwardly in said inner tub to agitate clothes and remove sediment therefrom, the invention comprising sediment removal means including in said inner tub a bottom wall connected to said sidewall of said inner tub for closing the open-bottom thereof and facilitating sediment removal in cooperation with the pulsations of said washing fluid, the configuration of said bottom wall being dished and having a plurality of radial ribs projecting into said inner tub, said bottom wall including an annular step down radially outwardly of said agitator means and said radial ribs and adjacent the connection of said bottom wall to said sidewall, said bottom wall including a series of holes radially outwardly of said step down and sufiiciently close to said step down to lie in the eddy current created thereat during each pulsation of washing fluid by the reciprocation of said agitator means in cooperation with the configuration of said bottom wall, whereby sediment removed from said clothes is carried by each pulsation of washing fluid between said radial ribs over said step down and entrained in said eddy current thereby to drop from said inner tub into said outer tub through the holes in said bottom wall as said eddy current References Cited UNITED STATES PATENTS 2,761,303 9/1956 Shelton 6823.7 2,807,949 10/1957 Molnar 6823.7 X 2,854,144 9/1958 Smith 210-382 2,869,348 1/1959 Shelton 68208 WILLIAM I. PRICE, Primary Examiner U.S. Cl. X.R. 68-23.6, 208 

